Method and apparatus for creating humidity gradients

Abstract

A method and apparatus for modulating humidity across large single-zone air conditioned spaces such as those typically found in supermarkets wherein conventional air conditioning means and a desiccant unit are combined to supply varying levels of humidity to different regions within the single-zone space.

What is claimed is: 
     
       1. A method for creating a humidity gradient within an air conditioning zone having a low humidity area and a high humidity area comprising the steps of: (a) withdrawing return air from the air conditioning zone;   (b) passing said return air through a desiccant unit to obtain low humidity supply air;   (c) passing said return air through an air conditioning unit to obtain high humidity supply air;   (d) injecting said low humidity supply air into said low humidity area with sufficient velocity and deflection of flow to penetrate with uniformity of greater than 60% in temperature and greater than 80% in humidity, to within two foot of the floor of said area; and   (e) injecting said high humidity supply air into said high humidity area.   
     
     
       2. The method of claim 1 wherein said air conditioning zone is the sales area of a supermarket. 
     
     
       3. The method of claim 2 wherein said low humidity area contains refrigeration cases. 
     
     
       4. The method of claim 2 wherein said high humidity area contains produce. 
     
     
       5. A method for creating a humidity gradient within an air conditioning zone having a low humidity area and a high humidity area, said high humidity area having a warm region and a cool region, comprising the steps of: (a) withdrawing return air from the air conditioning zone;   (b) passing said return air through a desiccant unit to obtain low humidity supply air;   (c) passing said return air through an air conditioning unit to obtain high humidity supply air;   (d) injecting said low humidity supply air into said low humidity area with sufficient velocity and deflection of flow to penetrate with uniformity of greater than 60% in temperature and greater than 80% in humidity, to within two foot of the floor of said area;   (e) injecting said high humidity supply air into said high humidity area;   (f) withdrawing ambient high humidity air from said cool area; and   (g) injecting said ambient high humidity air into said warm area.   
     
     
       6. The method of claim 5 wherein said air conditioning zone is the sales area of a supermarket. 
     
     
       7. The method of claim 6 wherein said warm area is the checkout area of said supermarket. 
     
     
       8. An apparatus for creating a humidity gradient within an air conditioning zone having a low humidity area and a high humidity area comprising: (a) a desiccant unit having an air input port and an air output port, a low humidity return air conduit, a low humidity supply air conduit, said low humidity return air conduit connecting said desiccant input port to said low humidity area, said low humidity supply conduit connecting said desiccant output port to said low humidity area; and   (b) an air conditioning unit having an air input port and an output port, a high humidity return air conduit, a high humidity supply air conduit, said high humidity return air conduit connecting said air conditioning input port to said high humidity area, said high humidity supply conduit connecting said air conditioning output port to said high humidity area.   
     
     
       9. The apparatus of claim 8 wherein said air conditioning zone is the sales area of a supermarket. 
     
     
       10. The apparatus of claim 9 wherein said low humidity area contains refrigeration cases. 
     
     
       11. The apparatus of claim 9 wherein said high humidity area contains produce. 
     
     
       12. The apparatus of claim 8 further comprising a desiccant unit blower capable of delivering said low humidity supply air to the end of said low humidity supply conduit adjacent said low humidity area at a terminal velocity (measured in cubic feet per minute) of at least eighty-five times the ceiling height (measured in feet). 
     
     
       13. The apparatus of claim 12 further comprising air diffuser apparatus at the terminal end of said low humidity supply conduit which directs a first predetermined amount of said low humidity air directly downward, and a second predetermined amount of said low humidity air outwardly at an angle of at least 30° from vertical. 
     
     
       14. The apparatus of claim 13 wherein said first predetermined amount of air is 2/3 of said low humidity air and said second predetermined amount of air is 1/3 of said low humidity air. 
     
     
       15. The apparatus of claim 13 wherein said low humidity supply air is directed into and substantially along the long axis of aisles in said conditioned zone, said aisles being defined by substatially parallel rows of shelves or refrigeration cases. 
     
     
       16. The apparatus of claim 13 wherein said low humidity supply air is directed downwardly across the front of one or more vertical glass-door refrigeration cases.